From 8ae664184c45def51ff0b61d4bd6c6671db6cb4f Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Thu, 5 Aug 2010 09:19:26 +0200 Subject: [PATCH] mtd: change struct flchip_shared spinlock locking into mutex This patch prevent to schedule while atomic by changing the flchip_shared spinlock into a mutex. This should be save since no atomic path will use this lock. It was suggested by Arnd Bergmann and Vasiliy Kulikov. Signed-off-by: Stefani Seibold Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/chips/cfi_cmdset_0001.c | 20 ++++++++++---------- drivers/mtd/lpddr/lpddr_cmds.c | 20 ++++++++++---------- include/linux/mtd/flashchip.h | 2 +- 3 files changed, 21 insertions(+), 21 deletions(-) diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 2fadb0239ba3..97d5546f9ea4 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -720,7 +720,7 @@ static int cfi_intelext_partition_fixup(struct mtd_info *mtd, chip = &newcfi->chips[0]; for (i = 0; i < cfi->numchips; i++) { shared[i].writing = shared[i].erasing = NULL; - spin_lock_init(&shared[i].lock); + mutex_init(&shared[i].lock); for (j = 0; j < numparts; j++) { *chip = cfi->chips[i]; chip->start += j << partshift; @@ -889,7 +889,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr */ struct flchip_shared *shared = chip->priv; struct flchip *contender; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); contender = shared->writing; if (contender && contender != chip) { /* @@ -902,7 +902,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr * get_chip returns success we're clear to go ahead. */ ret = mutex_trylock(&contender->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); if (!ret) goto retry; mutex_unlock(&chip->mutex); @@ -917,7 +917,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr mutex_unlock(&contender->mutex); return ret; } - spin_lock(&shared->lock); + mutex_lock(&shared->lock); /* We should not own chip if it is already * in FL_SYNCING state. Put contender and retry. */ @@ -933,7 +933,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr * on this chip. Sleep. */ if (mode == FL_ERASING && shared->erasing && shared->erasing->oldstate == FL_ERASING) { - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); @@ -947,7 +947,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr shared->writing = chip; if (mode == FL_ERASING) shared->erasing = chip; - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } ret = chip_ready(map, chip, adr, mode); if (ret == -EAGAIN) @@ -962,7 +962,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad if (chip->priv) { struct flchip_shared *shared = chip->priv; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); if (shared->writing == chip && chip->oldstate == FL_READY) { /* We own the ability to write, but we're done */ shared->writing = shared->erasing; @@ -970,7 +970,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad /* give back ownership to who we loaned it from */ struct flchip *loaner = shared->writing; mutex_lock(&loaner->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); mutex_unlock(&chip->mutex); put_chip(map, loaner, loaner->start); mutex_lock(&chip->mutex); @@ -988,11 +988,11 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad * Don't let the switch below mess things up since * we don't have ownership to resume anything. */ - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); wake_up(&chip->wq); return; } - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } switch(chip->oldstate) { diff --git a/drivers/mtd/lpddr/lpddr_cmds.c b/drivers/mtd/lpddr/lpddr_cmds.c index fece5be58715..04fdfcca93f7 100644 --- a/drivers/mtd/lpddr/lpddr_cmds.c +++ b/drivers/mtd/lpddr/lpddr_cmds.c @@ -98,7 +98,7 @@ struct mtd_info *lpddr_cmdset(struct map_info *map) numchips = lpddr->numchips / lpddr->qinfo->HWPartsNum; for (i = 0; i < numchips; i++) { shared[i].writing = shared[i].erasing = NULL; - spin_lock_init(&shared[i].lock); + mutex_init(&shared[i].lock); for (j = 0; j < lpddr->qinfo->HWPartsNum; j++) { *chip = lpddr->chips[i]; chip->start += j << lpddr->chipshift; @@ -217,7 +217,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) */ struct flchip_shared *shared = chip->priv; struct flchip *contender; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); contender = shared->writing; if (contender && contender != chip) { /* @@ -230,7 +230,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) * get_chip returns success we're clear to go ahead. */ ret = mutex_trylock(&contender->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); if (!ret) goto retry; mutex_unlock(&chip->mutex); @@ -245,7 +245,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) mutex_unlock(&contender->mutex); return ret; } - spin_lock(&shared->lock); + mutex_lock(&shared->lock); /* We should not own chip if it is already in FL_SYNCING * state. Put contender and retry. */ @@ -261,7 +261,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) Must sleep in such a case. */ if (mode == FL_ERASING && shared->erasing && shared->erasing->oldstate == FL_ERASING) { - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); @@ -275,7 +275,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, int mode) shared->writing = chip; if (mode == FL_ERASING) shared->erasing = chip; - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } ret = chip_ready(map, chip, mode); @@ -348,7 +348,7 @@ static void put_chip(struct map_info *map, struct flchip *chip) { if (chip->priv) { struct flchip_shared *shared = chip->priv; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); if (shared->writing == chip && chip->oldstate == FL_READY) { /* We own the ability to write, but we're done */ shared->writing = shared->erasing; @@ -356,7 +356,7 @@ static void put_chip(struct map_info *map, struct flchip *chip) /* give back the ownership */ struct flchip *loaner = shared->writing; mutex_lock(&loaner->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); mutex_unlock(&chip->mutex); put_chip(map, loaner); mutex_lock(&chip->mutex); @@ -374,11 +374,11 @@ static void put_chip(struct map_info *map, struct flchip *chip) * Don't let the switch below mess things up since * we don't have ownership to resume anything. */ - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); wake_up(&chip->wq); return; } - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } switch (chip->oldstate) { diff --git a/include/linux/mtd/flashchip.h b/include/linux/mtd/flashchip.h index f43e9b49b751..23cc10f8e343 100644 --- a/include/linux/mtd/flashchip.h +++ b/include/linux/mtd/flashchip.h @@ -92,7 +92,7 @@ struct flchip { /* This is used to handle contention on write/erase operations between partitions of the same physical chip. */ struct flchip_shared { - spinlock_t lock; + struct mutex lock; struct flchip *writing; struct flchip *erasing; };